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Variables & Constants

In Kyna, you give names to values using two declarations: var for values that can change, and const for values that stay fixed.

Declaring Mutable Variables with var​

Use var when you plan to reassign the value over time:

var count = 1;          # Type inferred as 'int'
print("Count:", count); # 1

count = count + 1;      # Reassignment
print("Count:", count); # 2

You can optionally write explicit nominal type annotations:

var username: str = "Alice";
var score: int = 100;
var isActive: bool = true;

Declaring Immutable Constants with const​

Use const for values that should never be reassigned after initialization. The compiler statically enforces immutability at build time:

const maxRetries: int = 3;
const serverEndpoint = "https://api.kyna.dev";

# Attempting reassignment causes a compile-time error:
# maxRetries = 5; # Error: cannot assign to const 'maxRetries'

Naming Conventions & Identifiers​

  • Identifiers must start with a letter (a-z, A-Z) or an underscore _.
  • Subsequent characters may include letters, digits (0-9), and underscores.
  • Identifiers are case-sensitive: servicePort and ServicePort are distinct bindings.
var total_requests = 10;
var maxBufferCapacity = 1024;
var _internalState = "READY";

Type Inference Rules​

When you omit a type annotation, Kyna infers the tightest nominal type from the right-hand expression:

var a = 42;             # inferred as int
var b = 3.14;           # inferred as float
var c = "hello";        # inferred as str
var d = true;           # inferred as bool
var e = [1, 2, 3];      # inferred as int list